The present invention relates to a suspension device of an automobile particularly having a structure in which a pair of lateral strut suspensions disposed vertically are connected to upper end portions by a strut bar extending in a width (lateral) direction of a vehicle body.
A strut-type suspension device has been widely known as one-type of independent suspension devices for four-wheel drive-type cars such as automobiles. This strut-type suspension device has a structure in which an upper end portion of each of strut suspensions formed to be expandable by winding a coil spring around an outer periphery of a shock-absorber is secured to a car body side portion and a lower end of the strut suspension is operatively coupled to a free end side portion of a suspension arm by which wheels are supported.
FIG. 6 is a sectional view showing the fixing structure of the upper portion of a strut suspension 61 of the type mentioned above, and with reference to FIG. 6, an inverted bowl-shaped strut support member 62 is inserted into the car body 63 from the lower side thereof through a mounting hole 64 formed to the car body 63 and then fastened at its flanged portion 65 by means of a plurality of stud bolts 66 and nuts 67 to the peripheral portion of the mounting hole 64. The upper end portion 68 of the strut suspension 61 is fastened and secured to a ceiling portion (upper end portion) 73 of the strut support member 62 together with a cushion bush 69, a rebound cushion 70 and a rebound washer 71.
Furthermore, in many structures, in order to improve rigidity of the car (automobile) body and suspension rigidity, a bilateral pair of strut support members 62 are coupled by means of strut bars 73. The strut bar 73 is formed from a metal bar pipe 74 having both ends to which substantially an annular (ring-shape) bar brackets 75 is secured by welding means, and a portion of the bar bracket 75 is fastened to the car body 63, i.e. peripheral portion of the mounting hole 64 together with the flanged portion 65 of the strut support member 62 by means of stud bolts and nuts 67.
In the structure of the conventional suspension device mentioned above, when the strut bar 73 is disposed, there is a possibility of the bar pipe 74 of the strut bar 73 interfering with a member such as engine, and in order to prevent such interfering, both the end portions of the bar pipe 74 are deeply bent downward and mounted to the bar bracket 75 thereby to increase the height of an intermediate portion of the bar pipe 74 with respect to a mounting surface portion of the bar bracket 75. That is, it is necessary to set a difference height H.sub.1 between the level A of the mounting surface of the bar bracket 75 and the height B of the intermediate portion of the bar pipe 74 as shown in FIG. 6.
However, as mentioned before, since the bar bracket 75 is fixed to the car body portion 63 together with the flanged portion 65 of the strut support member 62, the level A of the mounting surface is a low level, it is obliged to make extremely large the dimension of the difference height H.sub.1 to prevent the bar pipe 74 from interfering with the engine, for example. That is, in order to make large the dimension of the difference height H.sub.1, it is obliged to make large the bending curvature of both the end portions of the bar pipe 74. It therefore becomes difficult to maintain high rigidity of the entire structure of the strut bar 73.
Furthermore, since there are many limitations of spaces at the peripheral portion of the mounting hole 64 of the bar bracket 75 in association with other members or parts to be located, in order to eliminate this defect, it is necessary to form the bar bracket 75 manufactured through a sheet metal press working in a complicated shape, resulting in a weak mechanical strength.
Still furthermore, since the bar bracket 75 having substantially an annular structure surrounding the strut support member 62, it is necessary make the inner diameter of the bar bracket 75 larger than the outer diameter of the strut support member 62, which results in increased size and increased weight of the bar bracket 75.